/*
 * Copyright 2022 lzhpo
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.lzhpo.tracer.support;

import java.util.Map;
import java.util.Objects;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.slf4j.MDC;
import org.springframework.core.task.TaskDecorator;

/**
 * {@link TaskDecorator} delegate, inject maintain {@link MDC}'s context logic in child and parent
 * thread.
 *
 * @author lzhpo
 */
@Slf4j
@RequiredArgsConstructor
public class TracerTaskDecoratorDelegate implements TaskDecorator {

  private final TaskDecorator delegate;

  @Override
  public Runnable decorate(Runnable runnable) {
    Map<String, String> context = MDC.getCopyOfContextMap();
    Runnable finalRunnable = Objects.nonNull(delegate) ? delegate.decorate(runnable) : runnable;
    return () -> {
      try {
        MDC.setContextMap(context);
        finalRunnable.run();
      } finally {
        MDC.clear();
      }
    };
  }
}
